Description:

Stubs out a new helper. Pass the helper name, either CamelCased
or under_scored.

To create a helper within a module, specify the helper name as a
path like 'parent_module/helper_name'.

This generates a helper class in app/helpers and invokes the configured
test framework.

Example:

`rails generate helper CreditCard`

Credit card helper.
    Helper:     app/helpers/credit_card_helper.rb
    Test:       test/unit/helpers/credit_card_helper_test.rb